• Journal of Korea Ship Safrty Technology Authority
• /
• s.26
• /
• pp.36-46
• /
• 2009

본 연구에서는 문화관광부의 2008년도 스포츠연구개발사업의 취지에 맞게 소형선에서 가장 중요시되는 경량화를 위한 신소재를 적용하여 구조적으로 충분한 강도를 가지면서 아마추어들이 편하고 안전하게 모터보트 레이싱을 즐길 수 있도록 안전성 및 성능이 우수한 아마추어용 경정 보트를 개발하였다. 본 연구개발에 있어서 목재 및 FRP등 선체재료에 따른 구조해석을 수행하여 구조강도특성을 분석하고 워터제트형 경정 모터를 개발하여 경정 보트 시제품을 건조하여 시운전을 실시하는 등 안전성 및 성능을 확인하였다.

• Journal of the Korean Society of Physical Medicine
• /
• v.12 no.3
• /
• pp.111-117
• /
• 2017

PURPOSE: To determine the effect of weight ball throw training as a preparatory exercise before golf practice for 8 weeks on back muscle strength, weight shifting of lower body, head speed of club, and driving distance of amateur golfers. METHODS: A total of 18 subjects were randomly assigned to the experimental group (n=9) and the control group (n=9), respectively. For the experimental group, Weight ball throw training was provided to the height of waist and shoulder similar to golf swing with the following schedule: 3 kg weight ball throw training from the first week to the 4th week; 5 kg weight ball throw training from the 5th week to the 8th week. Before and after 8 weeks of training, back muscle strength, weight shifting of lower body, head speed of club, and driving distance of subjects in the two groups were measured. RESULTS: The experimental group showed significant differences in rotational back extension torque, weight shifting of lower body, head speed of club, and driving distance during golf swing (p<.05). However, the control group only showed significant difference in driving distance during golf swing (p<.05). Back extension torque, weight shifting of lower body, and head speed of club showed significant differences between the two groups during golf swing (p<.05). CONCLUSION: Weight ball throw training can positively change rotational back muscle strength, weight shifting of lower body, head speed of club, and driving distance of amateur golfers. Therefore, it might be used as an effective warming up exercise for amateur golfers.

• Korean Journal of Applied Biomechanics
• /
• v.13 no.3
• /
• pp.117-131
• /
• 2003

This study simulated the range of golf ball with different projection angles using a drive swing condition. For the simulation purpose, the differential equation of dynamics was induced by using Bernoulli's principle and average back spin frequency, instant velocity, and dimple of golf ball from amateur group, professional group, and Tiger Woods were chosen as the initial condition. The study result indicated that lift coefficient($C_{lift}$) relative to drag coefficient ($C_d$), 0.3 of differential equation was applied differently in terms of back spin Sequency, and when $C_{lift}$ was 0.4 for amateur, 0.5 for professional, and 0.7 for Tiger Woods the projection ranges of ball were closely matched with initial condition. With selected $C_{lift}$ and back spin frequency of initial condition, the ranges with different projection angle was measured as 193m ($13-17^{\circ}$) for amateur, 240m ($9-13^{\circ}$), professional and 273m ($9^{\circ}$)Tiger Woods, respectively. For the range in terms of back spin frequency and projection angle, the amateur group indicated relatively high spin frequency (70 RPS) and showed the maximal range (195m) with $13^{\circ}$ of projection angle. The tendency of longer range with higher projection angle was also found under the different conditions of spin frequency in this group. The professional group showed their maximal range (245m) with conditions of 60RPS of spin frequency and $9^{\circ}$ of projection angle. Their range was decreased dramatically when the spin frequency was reduced to 40-50 RPS. For Tiger Woods, the maximal range was found with 40RPS of spin frequency and the range was decreased notably when the spin frequency was above 40RPS.

• Korean Journal of Applied Biomechanics
• /
• v.26 no.2
• /
• pp.205-211
• /
• 2016

Purpose: The aim of this study was to analyze biomechanical factors and PMT (premotor time) of body muscles between elite college and amateur baseball players during the baseball batting motion. Method: Kinematic and electromyographic data were obtained for 10 elite college baseball players and 10 amateur baseball players who participated in this study. All motion capture data were collected at 200 Hz using 8 VICON cameras and the PMT of muscles was recorded using a Delsys Trigno wireless system. The peak mean bat speed and the peak mean angular velocities of trunk, pelvis, and bat with PMT of 16 body muscles were computed. These kinematic and PMT data of both groups were compared by independent t-tests (p < .05). Results: The pelvis, trunk, and bat showed a sequence of angular velocity value during baseball batting. The PMTs of right tibialis anterior, left gastrocnemius, external oblique, and erector spinae were significantly different between the two groups. Conclusion: The PMT of body muscles was related to the shifting of body and rotation of the pelvis and the trunk segment, and this action can be considered the coordinated muscle activity of the lower and upper body.

• Korean Journal of Applied Biomechanics
• /
• v.14 no.2
• /
• pp.167-178
• /
• 2004

The purpose of this study was to describe and compare the selected electromyographical muscle activities of trunk and hip during Professional and Amateur golfer's Iron swing. Using surface electromyography, we evaluated muscle activities in 6 male professional golfers and 6 male amateur golfers during the golf iron swing. Surface electrodes were used to record the level of muscle activity in the right abdominal oblique, left abdominal oblique, right erector spinae, left erector spinae, right rectus abdominis, left rectus abdominis, right gluteus maximus, left gluteus maximus muscles during the golfer's swing. These signals were compared with IEMG(Integrated EMG) which was normalized by %RVC(Reference voluntary contraction). The golf swing was divided into three phases: take away, forward swing-acceleration, follow-through. We observed patterns of trunk muscle activity throughout three phases of the golf swing. The results can be summarized as follows: LES(Left Erector spinae) had statistically significant difference in take away and forward swing-acceleration phases. It was showed no significant difference in follow-through phase.

• Journal of Fisheries and Marine Sciences Education
• /
• v.26 no.6
• /
• pp.1201-1208
• /
• 2014

The purpose of this study was to analyze the movements of the lower extremity muscle activities during a taekwondo kick motion called 'Balbutyeo Naeryeochagi', which was administered to players to improve their posture and muscle activity. Eight professional players and Eight amateur players were recruited as the subjects. Kinematic data were collected by EMG equipment, and the rectus femoris, tibialis anterior, biceps femoris, and medial gastrocnemius were measured using this instruments. This study processed the data using the Windows SPSS Ver. 18.0 to get an independent t-test, with the setting, p<.05. During the 'Balbutyeo Naeryeochagi' kick motion, there were small and inconsistent effects on each part. Results indicated that rectus femoris, tibialis anterior between two groups showed significantly difference in P1 and P2. Biceps femoris muscle activity in P2 showed large values in amateur group, and gastrocnemius showed no significantly difference between professional and amateur player during 'Balbutyeo Naeryeochagi' kick motion.

• The Bulletin of The Korean Astronomical Society
• /
• v.44 no.1
• /
• pp.66.1-66.1
• /
• 2019

성곡오색별빛마을은 경상남도 창녕군의 대산, 월곡, 안심, 연당, 연화 다섯 개의 마을 주민들이 만든 천문대시설이다. 창녕군 농어촌공사의 권역단위 종합정비사업으로 2013년 시작하여 2017년까지 건립되었다. 현재 성곡오색별빛마을 영농조합법인에서 시설 전반을 운영하고 있는데, 한국아마추어천문학회 경남지부에서 천문 프로그램을 운영하고 있다. 본 발표에서는 성곡오색별빛마을에 대한 소개와 더불어 최근 한국아마추어천문학회 경남지부의 천문지도사 양성프로그램과 정기관측회 및 교육기부를 통한 천체관측 문화 확산 및 경남메시에 마라톤 등에 대한 소개를 하고자 한다.

• Journal of Practical Engineering Education
• /
• v.16 no.1_spc
• /
• pp.11-19
• /
• 2024

Web programming courses are often included in university Computer Science programs as introductory and foundational computer programming courses. However, amateur programmers often have difficulty learning how to integrate HTML, CSS, JavaScript, and various preprocessors or libraries to create websites. Additionally, many web programming mistakes do not produce visible output in the browser. Therefore, in recent years, Front-End Code Playground (FECP) tools that incorporate HTML, CSS, and JavaScript into a single, online web-based application have become popular. These tools allow web coding to happen directly in the browser and provide immediate visual feedback to users. Such immediate visual feedback can be particularly beneficial for amateur coders to learn and practice with. Therefore, this study gathers data on various FECP tools, compares their differences, and provides an analysis of how such tools benefit students. This study concludes with an outline of the application of FECP to web programming courses to enhance the learning experience.

• Proceedings of the Korean Society of Propulsion Engineers Conference
• /
• 2006.05a
• /
• pp.398-404
• /
• 2006

Recently in Korea, rocket technology is being taken a wide scope as government planning to build Oeinaro-do space center and to select First Korean astronaut. But compared to development in USA, there is a lack of safety rules in amateur rocket. So it is very essential to meet some powerful legal safety rules for keeping pace with increasing popularization of rocket technology. Herein we discuss, in the field of rocket design, making, launching and collecting stage with considering the rules of IRR, NURA and NAR-HIAA.

• Korean Journal of Applied Biomechanics
• /
• v.16 no.2
• /
• pp.165-174
• /
• 2006

The purpose of this study was to review the relevant literature about coaching and thereupon, survey the coaching methods used for golfer lesson to reinterpret them and thereby, describe in view of kinetics the swing errors committed frequently by amateur golfers and suggest more scientific golfer coaching methods. For this purpose, kinetic elements were divided into precision and power ones and therewith, the variables affecting such elements were identified. On the other hand, swings were divided into address, take-back, back-swing, back-swing top, down-swing, impact and follow-through to determine 20 variables for each form and thereby, define their errors to determine the relations between their frequency and errors. For this study, a total of 60 amateur golfer were sampled, and their swing forms were photographed with two high-speed digital cameras, and the resultant images were analyzed to determine the errors of each form kinetically, which would be analyzed again with the program V1-5000. The results of this study can be summarized as follows; The kinetic elements could be identified as precision, power and precise power. Thus, setup and trajectory were classified into precision elements, while differences of inter-joint angles, cocking and delayed hitting. Lastly, timing and axial movement were classified into precise power elements. Three errors were identified in association with setup. The errors related with trajectory elements accounted for most (7) of the 20 errors. Three errors were determined for inter-joint angle differences, and one error was associated with cocking and delayed hitting. Lastly, one error was classified into timing error, while five errors were associated with axial movement. Finally, as a result of arranging the errors into a cross table, it was found that the errors were associated with each other between take-back and back-swing, take-back and follow-through, back-swing and back-swing top, and between back-swing and down-swing. Namely, an error would lead to other error repeatedly. So, it is more effective to identify all the errors for every form and correct them comprehensively rather than single out the errors and correct them one by one.